syms a s t u v x
f = exp(x/s^3); 
IL1 = ilaplace(f) 
g = 1/(t-a)^2; 
IL2 = ilaplace(g)
k = 1/(u^3-a^2); 
IL3 = ilaplace(k,x)
y = s^2*v/(s^3+v^2); 
IL4 = ilaplace(y,v,x)
